Stateful checkbox with multiple selection

Renders a checkbox list that uses a callback function to pass its selected value/values to the parent component.

• Use the useState() hook to create the data state variable and use the options prop to initialize its value.
• Create a toggle function that uses the spread operator (...) and Array.prototype.splice() to update the data state variable and call the onChange callback with any checked options.
• Use Array.prototype.map() to map the data state variable to individual <input type="checkbox"> elements. Wrap each one in a <label>, binding the onClick handler to the toggle function.

const MultiselectCheckbox = ({ options, onChange }) => {
  const [data, setData] = React.useState(options);

  const toggle = index => {
    const newData = [...data];
    newData.splice(index, 1, {
      label: data[index].label,
      checked: !data[index].checked
    });
    setData(newData);
    onChange(newData.filter(x => x.checked));
  };

  return (
    <>
      {data.map((item, index) => (
        <label key={item.label}>
          <input
            readOnly
            type="checkbox"
            checked={item.checked || false}
            onClick={() => toggle(index)}
          />
          {item.label}
        </label>
      ))}
    </>
  );
};

const options = [{ label: 'Item One' }, { label: 'Item Two' }];

ReactDOM.render(
  <MultiselectCheckbox
    options={options}
    onChange={data => {
      console.log(data);
    }}
  />,
  document.getElementById('root')
);